Despite being a professional metal finisher for 45 years I tended to think like a harmonica player when it came to our instruments. It's only been the past 2 years that I started to think more like a metal finisher when working on harps. That means not using goo's, goops, globs and goblins to fill voids to fix things. Peening the slide is a short term fix, and can ruins the harp in the process. A couple fixes that are easy to do is check the spring. Does it droop? IF it droops it means you have been re inserting the slide wrong and causing undo wear in the channel. See if you can roll the spring in its holder to make it stand straight out and not droop down or jet skyward.
Next, it is ok to flat sand the comb face on a CX-12. This will remove the high and low spots created through wear. You can de bur the slide by using fine grit sandpaper to remove any pieces of metal left behind from stamping out the holes in the slide. I use a 220 or 330 grit sanding sponge to roll the edge of the slide. The slide is placed in a bench vise that I glued craft foam paper to, to protect the mouthpiece parts when sanding.
If you have the patience to take the time it's easy to improve your harps with a few non evasive or damaging steps.
Mike
custom chromatics
